Korean Standard Nuclear Power Plant

1
Reduction Method of Spent Resin Generated from
SG BD  Ion Exchangers of PWR NPPS
SEP. 12, 2007
Sung, Ki-Bang kbsung_at_khnp.co.kr
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Contents
1. Introduction 2. Review of the early SGBD IX
Replace Criteria 3. Experiment of IX Resin
Capacity 4. Review of Experimental Results 5.
Conclusions
3
KHNPs RD Institute (1)

4
KHNPs RD Institute (2)

5
KHNPs RD Institute (3)

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1. Introduction (1)

• ? Background
• In Project of Kori 3,4 NPP PSR,
• Main system of LLW Resin SG BD Demineralizer
• Cause Secondary Side water pH control agent
  NH3 ? ETA-AVT
• The SGBD cation loads was increased
  about 23 times
• Spent Resin Radwaste Large volume and no
  Industrial waste
• Not easy to treat the ash, though spent resin
  is almost disposal object itself
• PSR Team treated as safety issue item
• PSR Team(NETEC) and Kori 2 Chemistry Section
  agreed to the problems and solved the
  sophisticated problems

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1. Introduction (2)
SG BD system functions
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1. Introduction (3)
Spent IX Resin Source
SFP IX 2.0ton (9.4)
CVCS IX 3.3ton (18.9)
LRW System IX1.7ton (7.1)
0
22.4 ton/Yr
2.12 t
3.71 t
7.95 t
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1. Introduction (4)
Ion Exchange Resin ?
Model of Ix Resin
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2. Review of the early SGBD IX Replace Criteria
(1)
In Domestic Plants,

•  IX Resin Replacement Procedures of SGBD IX
• - No standard Criteria of SGBD IX
• - Na was a typical ion to determine the IX
  removal capacity in many plants.
• - However, Na was not a typical ion to
  determine IX removal capacity other plants ( See
  the next page table )

In USA NPPs, (from EPRI report)

•  IX Resin Replacing Procedures of SGBD IX
• - 22 of 73 PWR plant didnt consider the Na
  ion as IX replacement Criteria

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2. Review of the early SGBD IX Replace Criteria
(2)
Table IX Exchanger Replacement Criteria of
Domestic Plants
Criteria Plnat IX Replacing Criteria IX Replacing Criteria note
Criteria Plnat Operation Demin. After Demin. note
A Plant Na 5ppb C.C 0.5 µS/? Na, Cl-, SO4-2 2 ppb  
B Plant Na. DF 1 Na. Cl-, C.C  DF 1 DF Inlet Conc.       Outlet Conc.
C Plant SO4-2 DF 1 SO4-2 DF 1  
D Plant C.C increase or Na2ppb C.C0.2 µS/? Na, Cl-, SO4-2 2ppb  
E Plant C.C0.5µS/?  Na, Cl-, SO4-2 2 ppb NA 1 Operation, 1 Stand-by
F Plant C.C0.1µS/? NA
G Plant C.C0.1µS/? Na3 ppb Cl-, SO4-25ppb NA
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3. Experiment of IX Resin Capacity (1)
Scheme and Shots
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3. Experiment of IX Resin Capacity (2)
Ion selectivity experiment with H-type IX resin
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3. Experiment of IX Resin Capacity (3)
ETA, NH4, Na Ion selectivity experiment with
Cs-type IX resin
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4. Review of Experimental Results (1)
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4. Review of Experimental Results (2)
Ion Absorbing Capacity on Resin

• Experiment 1/80000 of 2.5 ? which was equal
  to 30? of resin capacity
• and experiment was achieved for resin which is
  30 times of addicted chemical material
•   Experimental result (ion selectivity on resin)
  H  lt  NH4   ETA lt  Na  lt Cs  

Ion molecular weight ion concentration ion concentration system concentration (ppm) ratio with system ion concentration
Ion molecular weight (ppm)     (meq/l) system concentration (ppm) ratio with system ion concentration
ETA 61.08 122.16 2 3.5 35
NH3 17 34 2 0.2 170
Na 23 46 2 0.001 46000
Cs 133 266 2 0 8
total 101.08 202.16 8 3.701 - 
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4. Review of Experimental Results (3)
Ion Breakthrough Curve Characteristics

•   ETA
•       0.5 Output conc./Input conc. Breakthrough
  time(T) -gt     
• 
  (ETANH3) Na Cs 2T
  3T 4T
•     This phenomenon came from ETA/NH3, Na and
  Cs s different selectiveness.
•   NH3
•         NH3 was eluted after ETA and exchange
  reaction was faster than ETA.    ? NH3 was
  produced from ETA or N2H4 which removes Oxygen.
•   Na
•      Nas sensitivity was stronger than NH3 or
  ETA. So, Na was eluted after NH3 or ETA.
•   High Peak position of Na Conc. was
  overrode on Css conc. 1.0 meq/l(half input
  Conc.)
• ?  Cs extrude Na
•   Cs
•      Cs has S-shape breakthrough characteristics
  like single ion and it was absorbed on IX resin.
• Cs was not affected by other ions, and Its
  behavior look like single ion solution.

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4. Review of Experimental Results (4)
The resin replacement criteria of cation resin
  - ETA was not impurity in system, and should
not be removed at deminerlizer (On the contrary
it should be circulated)   - The small Na
leakage from new resins was not controlled and
excluded at demineralizer exchange criteria.   -
Even impurities by outside influx was suddenly
increased, the impurities concentration should be
decreased in proportion to circulating volume as
time passes. Impurities, concentration should be
decreased.     Table. The SG blowdown water
quality of PWR
Operation Operation mode Na criteria (ppb) Cl criteria (ppb)
Startup operation reload? cold standby (mode 6-5) 100 100
Startup operation hot shutdown (mode 4) 100 100
Startup operation hot standby (mode 3) 100 100
Startup operation startup operation (mode 2) 100 100
Reactor power operation reactor power (530) 100 100
Reactor power operation reactor power ( 30) 20 20
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4. Review of Experimental Results (5)
The resin replacement criteria of IX resin

• Na concentration should be less than 100ppb at
  maximum or stop operation.
• If the limited concentration at the second
  step is less than Na 100ppb,
• the concentration at Na DF 10 should be 10ppb.
• DF 10 of Na Spec value (20ppb) is 2ppb, and
  Max conc. of Na is 3ppb
• at operation over 30 generation. Therefore
  sum of them is less than 5ppb.   
• The water quality level is less than Na
  concentration(5ppb).
• Therefore, improvement of cation resin
  change criteria is that the Na outlet conc.
• is reasonable to be selected less than 5ppb.
• Cl , SO4-2 and Conductivity would be derived
  from system parameters as below.
• ? The resin exchange criteria of SG blowdown
  demineralizer
• -  exchange criteria of mixed bed Na, Cl
  5 ppb  
• -  reference exchange criteria SO4-2 5
  ppb,  C.C 0.3?/?

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4. Review of Experimental Results (6)
The SGBD Ion Exchangers cation/anion mixing ratio
Table Ion load for water quality of flow water
Item Ion Max.conc (ppb) M.W (g./mol) Ion load ( x 10-9 eq/l) Ion load ( x 10-9 eq/l)
Item Ion Max.conc (ppb) M.W (g./mol) Considered ETA, NH4 not considered ETA, NH4
ETA 5,000 61.08 81.86 NA
NH4 500 17.00 29.41 NA
N2H4 50 32.00 1.56 1.56
Na 20 23.00 0.87 0.87
total total total 115.05 3.78
Anion Anion Anion Max organic acid x 1 Max organic acid x 5
Cl- 20 35.50 0.56 0.56
SO4-2 20 96.06 0.42 0.42
SiO2- 100 60.08 1.66 1.66
Acetic acid 20 60.05 0.333 1.67
Glycolic acid 20 76.05 0.263 1.31
Formic acid 20 46.02 0.435 2.17
total total total 3.67 7.80
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4. Review of Experimental Results (7)
The SGBD Ion Exchangers cation/anion mixing ratio
Table.  Calculated Resin Volume with system ion
loads
Item Resin Item Resin Ion Load of System (x10-9 eq/l) Ion Load of System (x10-9 eq/l) Removal Capacity of Resin (eq /l resin) Calculated Resin Volume capacity (x 10-9 l resin) Calculated Resin Volume capacity (x 10-9 l resin)
Item Resin Item Resin ETA considering ETA not considering Removal Capacity of Resin (eq /l resin) ETA considering ETA not considering
Cation Cation 115 3.78 1.8 63.9 6.5
Anion Max organic acid x 1 3.67 3.67 1.2 3.1 3.1
Anion Max organic acid x 5 7.80 7.80 1.2 2.1 2.1
? SG BD demineralizers cation/anion resin mixing
ratio   - the ratio of cation and anion resin
was 10 1 considered ETA load    - the ratio of
cation and anion  resin was 1 3 excluded ETA
load    - The Mixing ratio of Resin (margin ETA
elution effects) 3 1
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5. Conclusions (1)
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5. Conclusions (2)
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5. Conclusions (3)
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Thank you for your attentions !